The present invention concerns a limb movement monitoring system.
Mobilizing a paretic limb, which occurs quite frequently for example after a stroke, is traditionally undertaken through hands-on physiotherapy. The therapist uses special grip techniques to move the weak arm, carefully paying attention to the limited range of motion that is often present. Such a treatment may restore the functional abilities of the affected limbs and may also reduce secondary complications like shoulder subluxations when an arm is affected. However, current budget pressure is limiting the amount of physiotherapy that can be prescribed for a person. At the same time, the administering of physiotherapy by a layperson poses its own difficulties.
U.S. Pat. No. 6,487,906 describes a sequence of low-force, high-compliance, long-extension, piezofilm-based sensors for a biofeedback system for self-monitoring of selected body motions. Flexible, large-area, piezofilm sensors are mounted on compliant but less flexible, larger-area, backbone structures so as to distribute localized stress anomalies and produce a useful, coherent, signal voltage for realtime body motion monitoring. The sensors are used in combination with body appliances that permit suitable placement of the sensors proximate to the body, in areas suitable for measuring body motion, such as twist, stretch and flexure. The sensors provide input signals to a small, self-contained signal processing and feedback module that generates a limited sequence of stepped announcements indicating the amount of motion detected. Instant feedback is provided to the user in the form of audible tones, colored lights, or other means intended to provide periphery feedback without directly interfering with the intended motion.
However, the art as taught in U.S. Pat. No. 6,487,906 is lacking in that when there is passive movement of a paretic or otherwise affected limb, the person moving the limb is not instructed in which direction the limb should be mobilized. Furthermore, an inexperienced person moving the limb is not warned when the beneficial scope of movement is exceeded, for example when mobilizing against a contracture.